Remove generated directories with 100s of files.

client/dom/generated/src/interface/TextTrackCue.dart

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// WARNING: Do not edit - generated code.
-
-interface TextTrackCue default _TextTrackCueFactoryProvider {
-
-  TextTrackCue(String id, num startTime, num endTime, String text, [String settings, bool pauseOnExit]);
-
-  String align;
-
-  num endTime;
-
-  String id;
-
-  int line;
-
-  EventListener onenter;
-
-  EventListener onexit;
-
-  bool pauseOnExit;
-
-  int position;
-
-  int size;
-
-  bool snapToLines;
-
-  num startTime;
-
-  String text;
-
-  final TextTrack track;
-
-  String vertical;
-
-  void addEventListener(String type, EventListener listener, [bool useCapture]);
-
-  bool dispatchEvent(Event evt);
-
-  DocumentFragment getCueAsHTML();
-
-  void removeEventListener(String type, EventListener listener, [bool useCapture]);
-}